📱(frontend) coordinate left/right panel visibility on tablet

On tablet, the place is too tight to have both
panels open at the same time. We have a fine-grained
control of the panel visibility to display panel
depend users interactions and responsive breakpoints.

src/frontend/apps/e2e/__tests__/app-impress/left-panel.spec.ts

@@ -1,6 +1,7 @@
 import { expect, test } from '@playwright/test';
 
 import { createDoc, goToGridDoc, verifyDocName } from './utils-common';
+import { tryFocusEditorContent } from './utils-editor';
 import { createRootSubPage } from './utils-sub-pages';
 
 test.describe('Left panel desktop', () => {
@@ -174,4 +175,47 @@ test.describe('Left panel responsive', () => {
     await verifyDocName(page, docChild);
     await expect(page.getByTestId('left-panel-mobile')).not.toBeInViewport();
   });
+
+  test('checks panel coordination on tablet sizes', async ({
+    page,
+    browserName,
+  }) => {
+    await page.setViewportSize({ width: 900, height: 1200 });
+    await page.goto('/');
+
+    await createDoc(page, 'tablet-doc-test', browserName, 1);
+
+    const leftPanel = page.locator('.--docs--resizable-left-panel');
+    const rightPanel = page.getByLabel('Table of contents side panel');
+
+    // Initially, left panel should be visible and right panel should be hidden
+    await expect(leftPanel).toBeInViewport();
+    await expect(rightPanel).not.toBeInViewport();
+    await tryFocusEditorContent({ page });
+    await page.keyboard.type('# Level 1');
+
+    // Open right panel, the left panel should hide
+    await page
+      .getByRole('button', { name: 'Show the table of contents sidebar' })
+      .click();
+    await expect(rightPanel).toBeInViewport();
+    await expect(leftPanel).toBeHidden();
+
+    // Open left panel, the right panel should hide
+    await page.getByRole('button', { name: /Show the side panel/ }).click();
+    await expect(leftPanel).toBeInViewport();
+    await expect(rightPanel).not.toBeInViewport();
+
+    // Close the left panel, the right panel should show
+    await page.getByRole('button', { name: /Hide the side panel/ }).click();
+    await expect(leftPanel).toBeHidden();
+    await expect(rightPanel).toBeInViewport();
+
+    // Close right panel, the left panel should stay closed
+    await page
+      .getByRole('button', { name: 'Hide the table of contents sidebar' })
+      .click();
+    await expect(rightPanel).not.toBeInViewport();
+    await expect(leftPanel).toBeHidden();
+  });
 });

src/frontend/apps/impress/src/features/docs/doc-editor/components/BlockNoteEditor.tsx

@@ -29,7 +29,7 @@ import { useConfig } from '@/core';
 import { useCunninghamTheme } from '@/cunningham';
 import { Doc } from '@/docs/doc-management';
 import { avatarUrlFromName, useAuth } from '@/features/auth';
-import { useRightPanelStore } from '@/features/right-panel/components/useRightPanelStore';
+import { useRightPanelStore } from '@/features/right-panel/stores/useRightPanelStore';
 import { useAnalytics } from '@/libs/Analytics';
 
 import { AI_FEATURE_FLAG, DEFAULT_LOCALE } from '../conf';

src/frontend/apps/impress/src/features/docs/doc-editor/components/comments/CommentSideBar.tsx

@@ -8,7 +8,7 @@ import CommentsIcon from '@/assets/icons/ui-kit/bubble-text.svg';
 import SortingResolvedSVG from '@/assets/icons/ui-kit/filter-notification.svg';
 import SortingOpenSVG from '@/assets/icons/ui-kit/filter_list.svg';
 import { Box, ButtonCloseModal, Text } from '@/components/';
-import { useRightPanelStore } from '@/features/right-panel/components/useRightPanelStore';
+import { useRightPanelStore } from '@/features/right-panel/stores/useRightPanelStore';
 
 import { useCommentSidebarStore } from './useCommentSidebarStore';
 

src/frontend/apps/impress/src/features/docs/doc-table-content/components/TableContentSideBar.tsx

@@ -8,7 +8,7 @@ import { Box, ButtonCloseModal, Text } from '@/components';
 import { useCunninghamTheme } from '@/cunningham';
 import { useEditorStore } from '@/docs/doc-editor/stores/useEditorStore';
 import { useHeadingStore } from '@/docs/doc-editor/stores/useHeadingStore';
-import { useRightPanelStore } from '@/features/right-panel/components/useRightPanelStore';
+import { useRightPanelStore } from '@/features/right-panel/stores/useRightPanelStore';
 import { MAIN_LAYOUT_ID } from '@/layouts/conf';
 
 import { Heading } from './Heading';

src/frontend/apps/impress/src/features/left-panel/stores/useLeftPanelStore.tsx

@@ -9,14 +9,22 @@ type TogglePanelArgs = {
 interface LeftPanelState {
   isPanelOpen: boolean;
   isPanelOpenMobile: boolean;
+  /**
+   * Depending on the responsive breakpoint, the panel can be auto-closed, and so
+   * auto-opened later on.
+   */
+  wasAutoClosed: boolean;
   togglePanel: (args?: TogglePanelArgs) => void;
   closePanel: (args?: TogglePanelType) => void;
+  autoClose: () => void;
 }
 
 export const useLeftPanelStore = create<LeftPanelState>((set, get) => ({
   isPanelOpen: true,
   isPanelOpenMobile: false,
+  wasAutoClosed: false,
   togglePanel: ({ value, type }: TogglePanelArgs = {}) => {
+    set({ wasAutoClosed: false });
     if (typeof value === 'boolean') {
       if (type === 'mobile') {
         set({ isPanelOpenMobile: value });
@@ -42,6 +50,7 @@ export const useLeftPanelStore = create<LeftPanelState>((set, get) => ({
     set({ isPanelOpen: !isPanelOpen, isPanelOpenMobile: !isPanelOpenMobile });
   },
   closePanel: ({ type }: Partial<TogglePanelType> = {}) => {
+    set({ wasAutoClosed: false });
     if (type === 'mobile') {
       set({ isPanelOpenMobile: false });
       return;
@@ -52,4 +61,5 @@ export const useLeftPanelStore = create<LeftPanelState>((set, get) => ({
     }
     set({ isPanelOpen: false, isPanelOpenMobile: false });
   },
+  autoClose: () => set({ isPanelOpen: false, wasAutoClosed: true }),
 }));

src/frontend/apps/impress/src/features/right-panel/components/RightPanel.tsx

@@ -9,7 +9,10 @@ import { TableContentSideBar } from '@/features/docs/doc-table-content/component
 import { HEADER_HEIGHT } from '@/features/header';
 import { useResponsiveStore } from '@/stores';
 
-import { RightPanelView, useRightPanelStore } from './useRightPanelStore';
+import {
+  RightPanelView,
+  useRightPanelStore,
+} from '../stores/useRightPanelStore';
 
 export const RightPanel = () => {
   const { t } = useTranslation();

src/frontend/apps/impress/src/features/right-panel/stores/useRightPanelStore.tsx

@@ -5,20 +5,37 @@ export type RightPanelView = 'tableContent' | 'comments';
 export interface UseRightPanelStore {
   isPanelOpen: boolean;
   activePanel: RightPanelView | null;
+  /**
+   * Depending on the responsive breakpoint, the panel can be auto-closed, and so
+   * auto-opened later on.
+   */
+  wasAutoClosed: boolean;
   setActivePanel: (panel: RightPanelView | null) => void;
   setIsPanelOpen: (isOpen: boolean) => void;
   togglePanel: () => void;
+  autoClose: () => void;
 }
 
 export const useRightPanelStore = create<UseRightPanelStore>((set) => ({
   isPanelOpen: false,
   activePanel: null,
+  wasAutoClosed: false,
   setActivePanel: (activePanel) =>
-    set(() => ({ activePanel, isPanelOpen: activePanel !== null })),
+    set(() => ({
+      activePanel,
+      isPanelOpen: activePanel !== null,
+      wasAutoClosed: false,
+    })),
   setIsPanelOpen: (isPanelOpen) =>
     set((state) => ({
       isPanelOpen,
       activePanel: isPanelOpen ? state.activePanel : null,
+      wasAutoClosed: false,
     })),
-  togglePanel: () => set((state) => ({ isPanelOpen: !state.isPanelOpen })),
+  togglePanel: () =>
+    set((state) => ({
+      isPanelOpen: !state.isPanelOpen,
+      wasAutoClosed: false,
+    })),
+  autoClose: () => set({ isPanelOpen: false, wasAutoClosed: true }),
 }));

src/frontend/apps/impress/src/layouts/MainLayout.tsx

@@ -11,6 +11,7 @@ import { DocEditorSkeleton, Skeleton } from '@/features/skeletons';
 import { useResponsiveStore } from '@/stores';
 
 import { MAIN_LAYOUT_ID } from './conf';
+import { usePanelCoordination } from './usePanelCoordination';
 
 type MainLayoutProps = {
   backgroundColor?: 'white' | 'grey';
@@ -56,18 +57,9 @@ export function MainLayoutContent({
 
   if (enableResizablePanel) {
     return (
-      <ResizableLeftPanel leftPanel={<LeftPanel />}>
-        <Box $direction="row" $width="100%" $position="relative">
-          <MainContent
-            backgroundColor={backgroundColor}
-            $flex="auto"
-            $padding="0"
-          >
-            {children}
-          </MainContent>
-          <RightPanel />
-        </Box>
-      </ResizableLeftPanel>
+      <MainResizableLayout backgroundColor={backgroundColor}>
+        {children}
+      </MainResizableLayout>
     );
   }
 
@@ -96,6 +88,32 @@ export function MainLayoutContent({
   );
 }
 
+interface MainResizableLayoutProps {
+  backgroundColor: 'white' | 'grey';
+}
+
+const MainResizableLayout = ({
+  children,
+  backgroundColor,
+}: PropsWithChildren<MainResizableLayoutProps>) => {
+  usePanelCoordination();
+
+  return (
+    <ResizableLeftPanel leftPanel={<LeftPanel />}>
+      <Box $direction="row" $width="100%" $position="relative">
+        <MainContent
+          backgroundColor={backgroundColor}
+          $flex="auto"
+          $padding="0"
+        >
+          {children}
+        </MainContent>
+        <RightPanel />
+      </Box>
+    </ResizableLeftPanel>
+  );
+};
+
 type MainContentProps = BoxProps & {
   backgroundColor: 'white' | 'grey';
 };

src/frontend/apps/impress/src/layouts/usePanelCoordination.tsx

@@ -0,0 +1,97 @@
+import { useEffect, useRef } from 'react';
+
+import { useLeftPanelStore } from '@/features/left-panel';
+import { useRightPanelStore } from '@/features/right-panel/stores/useRightPanelStore';
+import { useResponsiveStore } from '@/stores';
+
+/**
+ * Coordinates left/right panel visibility on tablet breakpoint.
+ * On tablet, the place is too tight to have both panels open at the same time, so we auto-close
+ * panels depending on the user actions.
+ */
+export function usePanelCoordination(): void {
+  const { screenSize } = useResponsiveStore();
+  const {
+    isPanelOpen: isLeftPanelOpen,
+    togglePanel: toggleLeftPanel,
+    autoClose: autoCloseLeft,
+  } = useLeftPanelStore();
+  const {
+    isPanelOpen: isRightPanelOpen,
+    setActivePanel: setRightActivePanel,
+    autoClose: autoCloseRight,
+  } = useRightPanelStore();
+
+  const prevScreenSizeRef = useRef(screenSize);
+  const prevRightPanelOpenRef = useRef(isRightPanelOpen);
+
+  /**
+   * Case 1 – entering tablet with both panels open → auto-close left.
+   * Case 2 – leaving tablet → reopen left if it was auto-closed.
+   * Case 3 – right panel opens on tablet → auto-close left if open.
+   * Case 4 – right panel closes on tablet → reopen left if auto-closed.
+   */
+  useEffect(() => {
+    const prevScreenSize = prevScreenSizeRef.current;
+    const prevRightOpen = prevRightPanelOpenRef.current;
+    prevScreenSizeRef.current = screenSize;
+    prevRightPanelOpenRef.current = isRightPanelOpen;
+
+    // Case 1 – entering tablet
+    if (screenSize === 'tablet' && prevScreenSize !== 'tablet') {
+      if (isRightPanelOpen && useLeftPanelStore.getState().isPanelOpen) {
+        autoCloseLeft();
+      }
+      return;
+    }
+
+    // Case 2 – leaving tablet
+    if (screenSize !== 'tablet' && prevScreenSize === 'tablet') {
+      if (useLeftPanelStore.getState().wasAutoClosed) {
+        toggleLeftPanel({ type: 'desktop', value: true });
+      }
+      return;
+    }
+
+    // Case 3 – right opens on tablet
+    if (screenSize === 'tablet' && isRightPanelOpen && !prevRightOpen) {
+      if (useLeftPanelStore.getState().isPanelOpen) {
+        autoCloseLeft();
+      }
+      return;
+    }
+
+    // Case 4 – right closes on tablet
+    if (screenSize === 'tablet' && !isRightPanelOpen && prevRightOpen) {
+      if (useLeftPanelStore.getState().wasAutoClosed) {
+        toggleLeftPanel({ type: 'desktop', value: true });
+      }
+      return;
+    }
+  }, [screenSize, isRightPanelOpen, autoCloseLeft, toggleLeftPanel]);
+
+  /**
+   * Exception – force-open / symmetric restore.
+   *
+   * Left opens on tablet (right is open)  → close right (save activePanel).
+   * Left closes on tablet (right was auto-closed) → reopen right.
+   */
+  useEffect(() => {
+    if (useResponsiveStore.getState().screenSize !== 'tablet') {
+      return;
+    }
+    if (isLeftPanelOpen) {
+      // User force-opened left: close right and remember which view was active.
+      if (useRightPanelStore.getState().isPanelOpen) {
+        autoCloseRight();
+      }
+    } else {
+      // User closed left: reopen right if it was auto-closed.
+      const { wasAutoClosed, activePanel: savedPanel } =
+        useRightPanelStore.getState();
+      if (wasAutoClosed && savedPanel) {
+        setRightActivePanel(savedPanel);
+      }
+    }
+  }, [isLeftPanelOpen, autoCloseRight, setRightActivePanel]);
+}